In agricultural and forestry sectors, there has been a strong desire for a component having high root-promoting activity and promoting plant growth, and many studies have been done. Under such circumstances, it is known that a succinic acid amide compound represented by the following general formula (1):Ar—(CH2)n—NHCO(CH2)2COOH   (1)wherein Ar represents an optionally substituted phenyl, naphthyl or indolyl group; and n is an integer of 1 to 4, or a salt thereof has an excellent root-promoting activity and is useful as a plant growth regulator (Patent Documents 1 and 2).
It is known that this succinic acid amide compound is produced by a microorganism belonging to the genus Bacillus, though it can also be obtained by chemical synthesis as described in Patent Documents 1 and 2 (non-Patent Document 1)
Patent Document 1: JP 1-255607 A
Patent Document 2: JP 2001-139405 A
non-Patent Document 1: Soejima et al., 1999, Isolation and purification of novel root-promoting substance N-(phenethyl)succinic acid amide, The Japanese Society for Chemical Regulation of Plants, the 34th Meeting Koen Yoshishu, pages 75-76
non-Patent Document 2: Environmental Health Bureau Ministry of Health and Welfare (Ed.) 1990, Chapter microbial food hygiene inspection guidelines, Japan Food Hygiene Association